Increasingly, I'm seeing people archive repositories to mark that a package / library / chef cookbook / whatever is no longer supported and won't be updated.
That's fair enough, but often these projects are still actively in use by other people for a fair while after the deprecation. During this period, there may be new issues that arise (e.g. due to changes in third-party / dependency libraries etc). Equally, end-users may find workarounds for previously reported issues.
Unfortunately because the repo is archived, there's no way for the end-user community to share knowledge about these.
For example, I recently hit this fatal bug on the poise-python cookbook https://github.com/poise/poise-python/issues/146 which was reported before it was archived. The original submitter also created a PR with a patch which wasn't merged. The structure of that project (a combined cookbook and rubygem) makes it quite complex to fork the project and use a modified version with the patch.
Knowing the bug would never be fixed in the package itself, I took another look at the problem and found a much simpler workaround that could be applied from the end-user code that calls it. It would be nice to be able to post that on the issue thread, to help other end-users that might hit the issue. As it stands, many would think it's just fatally broken and needs immediate wholesale replacement. In fact with a one-line replacement to calling code it can limp on a little longer, and be replaced when the time suits rahter than as a drop-everything firefighting exercise.
Likewise if I had needed to fork and merge, it would have been nice to be able to post a link to a working version of the package.
Completely understand (and agree) that archiving a repo should lock the PRs. But I think it would be nice to give maintainers the option of archiving a repo but leaving issues (either just comments on existing ones, or even allowing new ones) active. This could of course by default disable notifications to the owners/maintainers to allow them to archive and then ignore the project.
Thanks for this feedback! We're always working to improve GitHub and the GitHub Community Forum, and we consider every suggestion we receive. I've logged your feature request in our internal feature request list. Though I can't guarantee anything or share a timeline for this, I can tell you that it's been shared with the appropriate teams for consideration.